I found an interesting write-up of that soy and sperm story I blogged yesterday: Genistein in soya
The author makes a similar point to me: “The study does not reveal how genistein would affect in vivo human sperm.”
But, then he says, “In reality, Asian people use a lot of soya products, but they don’t seem to have a fertility problem.” What does he mean “in reality”? As opposed to “in the laboratory?”, “in virtuality?”, “on TV?”, what? Anyway, how does he know that Asian people don’t suffer fertility problems, is he assuming that because the populations of Asian countries are high that individuals are fecund?
Anyway, back to the science – the isoflavone genistein has been shown in separate studies to have estrogenic and anti-estrogenic properties and also to be a cancer protective. But, then others have shown it to cause uterine cancer…I don’t suppose we’ll ever know the truth, especially given that much of the research into the health benefits of soya products has been funded over the years by soya manufacturers.